Various types of breads have been developed so as to meet diversified consumer needs.
The breads are prepared from wheat flour, inter alia hard wheat flour obtained from hard-type wheat with a high protein content, such as Canada Western Red Spring wheat produced in Canada, Hard Red Winter wheat and Hard Red Spring wheat produced in the U.S., and Prime Hard wheat produced in Australia.
Breads prepared from hard wheat flour tend to lose moisture or invite staling of pasted starch when they are placed in show-cases of bakery shops at room temperature for a prolonged period. Such damaged breads become hard, and they often provide dry and rough texture and poor flavor. This tendency becomes more pronounced when breads are stored at low temperatures in a refrigerator.
It is also noted that when frozen breads prepared from hard wheat flour are thawed with the application of heat in a microwave oven, excessive loss of moisture or excessive denaturation of protein tends to occur, and the breads become hard, providing a sticky texture and poor flavor.
In order to solve the above-mentioned disadvantages, additives such as emulsifiers and gellatinized starch have conventionally been used as retrogradation preventive agents. Also, from the aspect of blending the starting materials, i.e., wheats, there have been employed several methods including (1) a method in which hard wheat flour is blended with soft wheat flour obtained, for example, from Norin 61 or Horoshiri wheat produced in Japan or from Australian Standard White wheat produced in Australia and/or from Western White wheat produced in the U.S. or from Soft wheat produced in Australia, or even with starch in some cases; and (2) a method in which hard wheat flour is not used; i.e., only semi-hard wheat flour and soft wheat flour are used.
However, the above-mentioned approaches cannot satisfactorily prevent deterioration of texture of breads, as they provide insufficient retrogradation preventive effect. Also from the viewpoint of health of consumers, addition of retrogradation preventive agents is not favorable. Moreover, when frozen breads prepared by the use of any one of the above-described improved methods are tasted after thawing, stickiness and hardness are decreased to provide somewhat better texture. On the other hand, moisture-retaining ability of the product decreases so that the product easily dries up and invites accelerated retrogradation. Furthermore, there is involved another disadvantage that the breads come to form lumps in the mouth, which are difficult to melt in the mouth. In order to overcome the above disadvantages involved in frozen breads, addition of auxiliary materials such as saccharides, oils and fats, etc. has also been studied. However, no satisfactory results have been obtained.
Cakes are prepared from soft wheat flour obtained from wheat, inter alia, soft wheat with a low protein content such as Western White wheat produced in the U.S. and Soft wheat produced in Australia.
When stored in refrigerators, cakes prepared from soft wheat flour tend to lose moisture or invite retrogradation of pasted starch. Such affected cakes become hard, and often provide dry and rough texture and poor flavor.
It is also noted that when sponge cakes, etc. prepared from soft wheat flour are stored in a frozen state and thawed at room temperature or in refrigerators, they provide poor flavor and disagreeable dry texture with lack of softness.
In order to solve the above-mentioned disadvantages, additives such as emulsifiers, gellatinized starch, modified starch, etc. have conventionally been used as retrogradation preventive agents. However, use of such additives does not provide satisfactory retrogradation preventive effects, but impede the flavor of cakes. Also, from the viewpoint of consumers' health, additives are not desirable. In addition, there is involved another disadvantage that when cakes prepared through use of such improved methods are thawed after being stored in a frozen state, they provide a sticky texture to the teeth and form lumps in the mouth, which are difficult to melt in the mouth.
In order to overcome the above disadvantages, addition of auxiliary materials such as saccharides, oils and fats, etc. has also been studied. However, no satisfactory results have been obtained.
Generally speaking, noodles such as udon, soba, and Chinese type noodles are prepared from a blend of flours including wheat flour, which is the primary component, and buckwheat flour, rice flour, barley flour, starch, etc. as required; plus salt, kansui, emulsifiers, gelling agents, colorants, etc. if necessary.
In recent years, the market is strongly oriented towards noodles of soft and thick or viscoelastic texture, and therefore, it is attempted to improve texture of noodles by the addition of starches, emulsifiers, or gelling agents. This trend is more clearly seen in boiled noodles that are stored in refrigerators or ambient temperature as well as in frozen noodles. This is because in the case of boiled noodles and frozen noodles which are stored in their gellatinized starch state, texture significantly deteriorates and they present weakened thick texture after being stored and re-heated, as compared to noodles that have been freshly boiled.
Use of those additives provides a soft and viscoelastic texture to some extent. However, the effect is not sufficient and there are drawbacks that taste and flavor are sometimes adversely affected.
In the meantime, it is accepted that deterioration in texture of boiled noodles is partly due to retrogradation of gelatinated starch. Starch is composed of linear amylose and amylopectin, wherein glucose units are linked by .alpha.l-4 linkages, but the latter also contains some branching .alpha.l-6 bonds. Starch that contains only very small amounts of amylose is called waxy starch. It has been attempted to overcome deterioration of texture attributed to retrogradation by means of adding, to noodles, materials with a high content of waxy starch, such as waxy rice flour, waxy rice starch, waxy corn flour, and waxy cornstarch. Such attempts have not yet produced satisfactory results.